3.4 Effects of different substrates on rhizosphere microbial
communities
The dominant bacterial species of each group were similar (Fig.5). At
the phylum level, Proteobacteria and Chloroflexi were the
top two dominant bacteria in all samples, and Proteobacteriaaccounted for 16.94%-21.55%, and Chloroflexi accounted for
14.82%-22.48%. However, the influences of different substrates on the
proportion and composition of dominant bacteria were different. No
difference in the relative abundance of Chloroflexi among ME, VE,
or VR groups, but it was lower in these three treatment groups than in
CK group, whereas the relative
abundance of Chloroflexi in the CE group was higher than that in
CK group. Additionally, the relative abundance ofDesulfobacterota and Nitrospirota in 4 treatment groups
was higher than that in CK, while the relative abundance ofAcidobacteriota was the opposite.
On day 40, Ace, Chao, Sobs, and Shannon indexes in all 4 treatment
groups were higher than CK (Table S1), among which group VE was the
highest, followed by group VR. The ME, VE, and VR groups exhibited a
lower Simpson index than CK group, while CE group displayed a higher one
than CK. These results indicated that the substrate addition could
increase diversity and abundance of rhizosphere microorganisms.